HOHHOT, (Xinhua) -- a kind of industrial solid waste with huge stock in Inner Mongolia Autonomous Region---fly ash, went abroad for the first time and became a unique resource. In March, 2021, a special train loaded with 50 containers and 3,200 tons of fly ash slowly departed from Jinfengyuan loading line in Hohhot, headed for Yantai Station in Shandong Province, which would be transferred to the ship via Yantai Port and sent to Guinea, a West African country on the other side of the ocean. The fly ash which came from Inner Mongolia would be supplied to Chinese-funded enterprises in Guinea after long-distance transportation, and be used as building materials for local railway and bridge construction. According to reports, the fly ash in Inner Mongolia will be shipped regularly in the future. Even though under the shadow of the global pandemic, the fly ash still rise to the challenge, opening up a new space for comprehensive utilization of industrial solid waste.

China's fly ash is unevenly distributed,

rich in north and scarce in the south

Fly ash is one of China’s largest industrial solid wastes and China is the largest producer of fly ash in the world. Fly ash refers to the fine fly ash and slag obtained from the flue gas collected by dust collector in coal-fired power plants and power plants with comprehensive utilization of coal gangue and slime resources. The amount of fly ash is very large, usually one ton of fly ash will be produced for every two tons of coal consumed. As China is rich in coal resources, the development of electric power industry is still dominated by coal-fired thermal power generation with fly ash processing in recent years. Therefore, places boasting abundant coal resources and coal enterprises such as thermal power and coal chemical industry produce a large amount of fly ash every year.

China's fly ash still faces a serious unbalanced regional distribution. In developed areas such as the southeast coast and some large cities, fly ash has been fully utilized, and even the supply is in short supply. However, in Shanxi, Inner Mongolia, Ningxia, Xinjiang and other coal-fired power producing areas, the utilization rate of fly ash is very low due to the large amount of fly ash produced and the limited absorptive capacity.

New characteristics of resource utilization of fly ash in China

Extending the transportation radius from north to southeast is a new feature of accelerating the utilization of fly ash. Due to the limitation of transportation cost, the cross-regional logistics of fly ash mainly adopted the relatively low-cost transportation mode of water transportation in the past. Accordingly, the areas to realize the outward transportation of fly ash are mainly coastal, riverside areas and areas by the river. Fly ash from Liaoning, Hebei, Shandong has made up for the market gap of fly ash in Guangdong, Fujian, Shanghai and other regions.

At present, the railway transportation of fly ash in China has taken an important step. Although this year's national fly ash market was affected by the overall environment, the sales volume and price of fly ash declined, the railway transportation of fly ash ushered in an important development opportunity despite the large regional differences in price of fly ash. However, it is undeniable that the industrial chain of railway transportation of fly ash is not perfect at present, and it is necessary for the government, enterprises, supporting service units and other parties to strengthen exchanges and collaboration to jointly promote the development of railway logistics industry of fly ash.

Concrete industry is a big eater of fly ash

The comprehensive utilization of fly ash in China has gone through three development stages: "storage-oriented", "combination of storage and use" and "use-oriented". At present, China's fly ash is mainly used in building materials, road engineering, backfill engineering, agriculture, mineral extraction and other fields. Among them, the comprehensive utilization of fly ash in cement, concrete, wall materials and other building materials accounts for about 90% of the total utilization while the amount of fly ash used in cement admixture production accounts for about 38% of the comprehensive utilization of fly ash.

Fly ash can also be used as admixture for concrete, accounting for about 14% of the comprehensive utilization of fly ash.

In the field of building materials deep processing market, the amount of fly ash used in building materials deep processing products accounts for about 26% of the comprehensive utilization of fly ash. The deep processing of fly ash has developed rapidly in recent five years, which is related to the rapid development of science and technology and the sound laws related to environmental protection. It can be seen that the deep processing of fly ash may also open up new uses.

Compared with foreign developed countries, the comprehensive utilization rate of fly ash in China is still relatively low, and the technology and level of comprehensive utilization of fly ash are not high. However, with the development of utilization technology, the utilization of China's fly ash is constantly improving. After entering the 21st century, the comprehensive utilization rate of China's fly ash has steadily increased in recent 20 years.

The urgent need to improve the comprehensive utilization of fly ash

China is a major coal producer, and coal is the basic fuel for electric power production. Although we are changing the power energy structure, the status of coal burning as the power industry will continue for some time. With the development of the country, the demand for electric power keeps increasing despite the decrease in proportion of thermal power in the energy structure. Therefore, it is expected that the output of fly ash in China will keep increasing in the future.

In the future, the amount of fly ash in China will remain at a high level, and the underdeveloped areas in western China will face more serious problems of new and old fly ash stockpiling and overcapacity. At present, the utilization of fly ash is still dominated by building materials, and the added value of products is low. In the future, the development and utilization channels of fly ash resources will be continuously broadened and extended.